<template>
  <view>
    <!-- 使用自定义的搜索组件 -->
    <my-search @click="gotoSearch"></my-search>
    <view class="scroll-view-container">
      <!-- 左侧的滚动视图区域 -->
      <scroll-view 
      scroll-y="true"
      class="left-scroll-view"
      :style="{height:wh+'px'}"
      >
        <view 
         v-for="(item,i) in cateList"
         :key="i"
         :class="['left-scroll-view-item',i === active ? 'active':'']"
         @click="activeChanged(i)"
         >{{item.cat_name}}</view>
      </scroll-view>
      <!-- 右侧的滚动视图区域 -->
      <scroll-view
      scroll-y="true"
      class="right-scroll-view"
      :style="{height:wh+'px'}"
      :scroll-top="scrollTop"
      >
      <!-- 遍历二级分类列表 -->
        <view class="cate-lv2" v-for="(item2,i2) in cateLevel2" :key="i2">
          <!-- 二级分类标题 -->
          <view class="cate-lv2-title">
            /{{item2.cat_name}}/
          </view>
          <!-- 遍历三级分类列表 -->
          <view class="cate-lv3-list">
            <!-- 三级分类的item -->
            <view 
            class="cate-lv3-item" 
            v-for="(item3,i3) in item2.children"
            :key="i3"
            @click="gotoGoodsList(item3)"
            >
              <image :src="item3.cat_icon"></image>
              <text>{{item3.cat_name}}</text>
            </view>
          </view>
        </view>
      </scroll-view>
    </view>
  </view>
  </view>
</template>

<script>
  import badgeMix from '@/mixins/tabbar-badge.js'
  export default {
    mixins:[badgeMix],
    data() {
      return {
        //窗口的可用高度
        wh:0,
        //分类数据列表
        cateList:[],
        //左侧选中项的索引,默认选择第0项
        active:0,
        //二级分类列表
        cateLevel2:[],
        //滚动条距离顶部的距离
        scrollTop:0,
      };
    },
    onLoad() {
      // 获取当前手机信息
      const sysInfo = uni.getSystemInfoSync()
      // 获取手机剩余可用高度
      this.wh = sysInfo.windowHeight - 50 
      //调用获取分类列表数据方法
      this.getCateList()
    },
    methods:{
      // 获取分类列表数据方法
       async getCateList(){
        const {data:res} = await uni.$http.get('/api/public/v1/categories')
        if(res.meta.status !== 200)return uni.$showMsg()
        this.cateList = res.message
        //为二级分类赋值
        this.cateLevel2 = res.message[0].children
      },
      activeChanged(i){
        this.active = i
        //当一级分类变化的时候，为二级分类重新赋值
        this.cateLevel2 = this.cateList[i].children
        //重置scrollTop
        this.scrollTop = this.scrollTop ? 0 : 1
      },
      //点击三级分类跳转到商品列表界面
      gotoGoodsList(item3){
        uni.navigateTo({
          url:'/subpkg/goods_list/goods_list?cid='+item3.cat_id
        })
      },
      //跳转到分包中的搜索页面
      gotoSearch(){
        uni.navigateTo({
          url:'/subpkg/search/search'
        })
      },
    }
  }
</script>

<style lang="scss">
.scroll-view-container{
  display: flex;
  .left-scroll-view{
    width: 120px;
    .left-scroll-view-item{
      line-height: 60px;
      background-color: #f7f7f7;
      text-align: center;
      font-size: 12px;
      &.active{
        background-color: #ffffff;
        position: relative;
        &::before{
          content: ' ';
          display: block;
          width: 3px;
          height: 30px;
          background-color: #c00000;
          position: absolute;
          left: 0;
          top: 50%;
          transform: translateY(-50%);
        }
      }
    }
  }
  
  .cate-lv2-title{
    font-size: 12px;
    font-weight: bold;
    text-align: center;
    padding: 15px 0;
    }
    
    .cate-lv3-list{
      display: flex;
      flex-wrap: wrap;
      .cate-lv3-item{
        width: 33.33%;
        margin-bottom: 10px;
        display: flex;
        flex-direction: column;
        align-items: center;
        image{
          width: 60px;
          height: 60px;
        }
        text{
          font-size: 12px;
        }
      }
    }
}
</style>
